DM-DD OFDM-RoF System With Adaptive Modulation Using a Gain-Switched Laser

We propose a 60-GHz orthogonal frequency division multiplexing (OFDM) radio over fiber system based on direct modulation-direct detection using an externally injected gain-switched DFB laser with adaptive modulation format. Power fading due to chromatic dispersion is mitigated by optimizing the bias current. Adaptive modulation for OFDM is used to improve the signal transmission performance. A 15.31-Gb/s 60-GHz OFDM signal generation and transmission over 25-km standard single-mode fiber is experimentally demonstrated.